1. Field of the Invention
This invention relates to an aryl ester compound which can be used mainly as a curing agent for an epoxy resin and can give a cured product having a low dielectric constant and a low dielectric loss tangent; an epoxy resin composition using the same, and a laminate prepared using the epoxy resin composition. These are suitable for a molding material, a paint and varnish, a coating material, a civil engineering material, a constructional material and in particular, in the electric or electronic uses which work at high-frequency region, for example, a resin for laminate or an IC-sealing resin.
2. Description of the Prior Art
Among the epoxy resins used in the electric and electronic uses, the resin for a printed wiring board has heretofore been mainly a combination of a bisphenol type epoxy resin with a dicyandiamide. In recent years, the resin has been required to have a low dielectric constant for the purpose of the improvement of signal velocity and the impedance-matching of circuit as the printed wiring board has been made thinner and more multiple in layer and also required to have a low dielectric loss tangent for the purpose of diminishing the signal transmission loss as a high-frequency signal is used. For these purposes, a method of combining a conventional epoxy resin with a thermoplastic resin having a low dielectric constant and a low dielectric loss tangent has been devised. For example, a method of modifying the epoxy resin with a reactive polybutadiene resin and a method of dispersing a polytetrafluoroethylene resin powder have been proposed.
However, in these prior techniques, the epoxy resin which is the basic material has a high dielectric constant, and hence, the proportion of the thermoplastic resin to be combined becomes large in order to achieve the desired dielectric constant, and hence, the heat resistance, adhesiveness, dimension stability, chemical resistance and the like which are characteristic features of the epoxy resin are damaged. Therefore, there have been earnestly desired such an epoxy resin curing agent that a cured product having a low dielectric constant and a low dielectric loss tangent can be obtained without damaging the heat resistance, adhesiveness and processibility of an epoxy resin and an epoxy resin composition containing the curing agent.
The present inventors have made extensive research on the functional group structure and skeletal structure of a compound capable of thermal cure reaction with an epoxy resin, and have consequently found that an epoxy resin composition comprising a compound having a specific functional group structure and a specific skeletal structure can meet the above-mentioned purposes.